Purchase a low-end Microsoft phone in the near future, and you’ll discover that the built-in web browser is made by a competitor: Opera. They’re also going to encourage existing device owners to ditch their old default browser and upgrade to Opera Mini.

What motivated Microsoft to make the change? Likely the same thing that caused Opera to ditch in-house efforts to build a browsing engine and switch over to Google’s Chromium core in Opera 15. Sometimes a company decides that there’s an alternative out there and that its own resources could be better allocated elsewhere.

When Microsoft acquired Nokia, the company didn’t seem particularly keen on continuing their featurephone lines. Last month, Microsoft predictably revealed that they were indeed going to wind down production of Asha and S40 phones and would focus instead on building inexpensive Windows phones for the low-end and emerging markets.

Microsoft isn’t just EOLing Xpress because of job cuts and the desire to re-assign developers. Like Opera, Xpress includes a feature that can compress browsing data by routing a user’s requests through proxy servers. Microsoft now owns those Nokia servers, and they likely aren’t all that interested in keeping them running.

It’s nice to see Microsoft encouraging Asha and S40 users to upgrade to a browser that’s actually going to be maintained. Opera is certainly excited about the deal, and they should be.

Even on featurephones, people are surfing the web more and more every day. Opera just picked up a few million additional users, and if people like what they see, who knows? They might just want to stick with a phone that can run Opera Mini the next time they buy — and that would mean not buying a Windows Phone.

Microsoft’s decision to replace Xpress with Opera could actually wind up driving more users to Android.